Modern aircrafts generally include an onboard computing system called flight management system (EMS). The FMS provides the flight crew with information on future states of the aircraft along a selected flight path. This information is based on performance predictions of the aircraft during various phases of the flight. Typically, the flight plan includes a climb flight phase which starts from an acceleration altitude and is considered to be completed once the aircraft reaches a cruise altitude (also referred to as “top-of-climb”). Predictions of time, fuel consumption, altitude, aircraft speed and other parameters at en route points until the top-of-climb provide useful information about the future performance of the aircraft. Typically, such predictions are displayed to the flight crew.
Currently, the criteria used for obtaining the information are preset or the parameter values may be assumed. For example, climb angle, fuel flow and true air speed (TAS) may be considered to vary linearly with the altitude. Further, constant values may be considered for parameters, such as air speed, lapse rate, temperature and the like to obtain the information. This can result in providing inaccurate information to the flight crew during the climb flight phase.